It’s scare tactics.
That’s exactly the NLRB’s point. The NDA doesn’t necessarily have to be legally enforceable to be unlawful.
A common way the NLRB examines these types of things is by how a reasonable person would perceive it. Even if a lawsuit was filed to challenge the enforceability of the NDA and it was found unenforceable, the NLRB would still be able to argue a “reasonable person” would believe it was enforceable, and accordingly any restrictions on protected rights presented by the NDA would be unlawful.
Focusing on freeloaders rather than those in need is problematic. There will always be freeloaders, and sure, we should always aim to minimize their numbers. But is it worth it to deny those with genuine need who vastly outnumber the relatively miniscule number of freeloaders?
Also, papyrus sucks.